Cardiovascular Exercise- The Big Picture

Patient Tip of the Week: “At home we started putting on music instead of the TV as background noise.  We are finding we just move more because of the music and are not tempted to sit in front of the TV” 

Lets continue our chat about cardiovascular exercise.  Staying with the “seeing the forest for the trees” metaphor,  lets look at the forest, the “big picture” to know we are using our exercise time well.

There are a few factors we use to measure the amount of exercise – how long are you moving for? how hard are you exercising? how many days a week/ times a day?  What type of movement are you doing?

First of all, movement is good – much better than not moving.  Part of seeing the big picture is getting out of the mindset of “good or bad” exercise.  Our bodies were made to move in a variety of ways and durations.  So variety is good.  Some intense, some easy, some short bouts some long bouts, and moving in ways that use our bodies in different ways to avoid getting stuck in movement patterns.  Some movements are not healthy ways to move our bodies (ie: doing dips for the triceps) so you have to choose your exercise as wisely as you choose your food,  but in general movement beats sitting. 

How Hard to Exercise and For How Long:

One of the simplest tools keeping an eye on your own exercise intensity is Rating of perceived Exertion (RPE) .  (the article in this link uses a scale of 6-20 instead of 1-10 – the idea is the same).  This is a tool for simply noticing your breathing level during exercise.  Remember from the last post that the increased carbon dioxide (CO2) when we exercise triggers faster breathing.  As we push harder during exercise more CO2 is produced.  So breathing level is actually a way to measure what is happening at the cells, just as we are tryng to do with heart rate. 

However, with RPE it is often and easier way to get a quick and accurate measure of how hard you are working compared to what your body can tolerate.  In order to know what your heart rate should be you would need a  maximal exercise test (ie: stress test – no fun!) or we can use your age to predict your maximal heart rate.  The problem is, the prediction has a plus or minus 15 beat error!  That means that when the cardio machine tells you what your heart rate should be – your heart rate could actually need to be 15 beats per minute (bpm) higher or lower.  For example, the treadmill tells you to go for a heart rate of 140bpm. In actuality, you should be at 125bpm or possibly  at 155bpm  – that is a big difference. 

AND certain medications, such as metoprolol, lower heart rate – so this equation would not work and could cause you to push way to hard for your body.  I have had many patients mislead about this in gyms because the effects of medicaitons are not considered in recommending exericse levels. (but that is another s”oap box” for another blog)

Using RPE is easier and helps us listen to our body. The goal is moderate to somewhat hard. Comfortable challenge. If it is uncomfortable, it is too much and increases risk of injury.  Just starting out? Keep it at light intensity.    Simple but accurate!

And… while we are talking intensity – ignore the “fat burning” or weight loss ranges.  Sounds too good to be true to burn more fat right… yep!  Burning more fat means burning fewer calories per minute.   Just work at that comfortable challenge range and your body will burn as many calories as it can safely and effectively.  As you do this more, it will adapt and you will be able to burn more calories per minute.

For example:  Jane is a 250lb woman.  She wants to lose weight but fatigue gets in the way of exercising at the level she used to do.  She starts walking 3 days a week at 2mph, a comfortable challenge pace for her, for 30 minute and burns 157 calories each workout. 

Gradually this level becomes easy and she can eventually walk at 3mph. As her body has become stronger this is now a comfortable challenge and 2pm is easy.  She is now burning 247 calories per workout.  Same 30 min but 90 more calories burned.  Her consistency has paid off and her body has better stamina in everyday life is better too.  She gradually ads a couple more days a week.  Yay Jane! 

But wait – she is an accountant and tax season is here!  Oh no… she does not have time for her 30 min workout.  She does not give up. She decides to do 10 minutes in the morning, 10 in the afternoon and 10 in the evening – guess what – same calories burned – nothing lost!  AND the exercise saves her from the stress of the season!  Double-Yay Jane!

Lets back up though – what if when she was starting out even 30 min was too much?  What if she did 10 min bouts at 2mph 5x per day? Guess what – she would burn a  total of 262 calories in that 50 min of total walking time.  Wow! more than even at 3pmh for 30 min!

What??  Slower shorter walks and more calories burned! yep!   Ideally, if she can do her 30 min workout each day and then a few 5-10 min walks periodically during her day she would be getting great  calorie buring and health benefits. 

Bottom line – you’ve got lots of options!  Lack of time and energy should not be a reason not to move.  Movement, frequent movement is key.    NOW we are seeing the whole forest instead of just the “exercise” tree!

“But what about sweating – I am not going to work up a sweat during those little 10 min walks!”  Sweat is not a great way to tell if you are burning calories and you dont have to sweat to get a good workout.  Sweat rate depends on tempature, wind, clothing, activity, genetics, hydration, etc.  Sweat does NOT melt away fat so don’t make yourself sweat… its a myth (Busted!)

What Type of Cardio is Best? – Walking is great even if has to be in smaller bouts to keep it comfortable.  It is the natural movement we are designed to do most.     Other types of cardio are great, as long as you enjoy it, you can keep the intensity at a comfortable challenge and it does not increase muscluloskeletal pain.  

Keep Moving, Be Well

Janet